<template>
    <div class="upload-file">
        <el-upload multiple :action="uploadFileUrl" :data="fileData" :before-upload="handleBeforeUpload"
            :file-list="fileList" :limit="limit" :on-error="handleUploadError" :on-exceed="handleExceed"
            :on-success="handleUploadSuccess" :on-progress="handleProgress" :show-file-list="false" :headers="headers"
            class="upload-file-uploader" ref="upload">
            <!-- 上传按钮 -->
            <slot>
                <el-button type="primary">选取文件</el-button>
            </slot>
        </el-upload>
        <!-- 上传提示 -->
        <div class="el-upload__tip" v-if="showTip">
            请上传
            <template v-if="fileSize">
                大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b>
            </template>
            <template v-if="fileType">
                格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b>
            </template>
            的文件
        </div>
        <!-- 文件列表 -->
        <transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear" tag="ul"
            v-if="showFileList">
            <li :key="file.uid" class="el-upload-list__item ele-upload-list__item-content"
                v-for="(file, index) in fileList">
                <el-link :href="`${baseUrl}${file.url}`" :underline="false" target="_blank">
                    <span class="document">
                        {{ getFileName(file.name) }}
                    </span>
                </el-link>
                <div class="ele-upload-list__item-content-action">
                    <el-link :underline="false" @click="handleDelete(index)" type="danger">删除</el-link>
                </div>
            </li>
        </transition-group>
        <div class="flex flex-direction justify-center align-center" v-if="upLoading"
            style="position: fixed;top: 0;bottom: 0;left: 0;right: 0;height: 100vh;width: 100vw;z-index: 9999999;background-color: rgba(0,0,0,0.8);">
            <div v-loading="upLoading" element-loading-text="" element-loading-background="rgba(0, 0, 0, 0)"
                style="width: 10px;height: 10px;"></div>
            <span style="font-size: 16px;color: var(--el-color-primary);margin-top: 40px;">上传进度：{{ upProgress }}%</span>
        </div>
    </div>
</template>

<script setup>
import { genFileId, ElMessage } from 'element-plus'
import { computed, getCurrentInstance, reactive, ref, watch } from "vue";

const props = defineProps({
    modelValue: {
        type: [String, Object, Array],
    },
    limit: {
        type: Number,
        default: 0,
    },
    fileSize: {
        type: Number,
        default: 0,
    },
    fileType: {
        type: Array,
        default: ['video/mp4'],
    },
    // 是否显示提示
    isShowTip: {
        type: Boolean,
        default: false,
    },
    // 超出上传数量时，是否覆盖继续上传
    isExceed: {
        type: Boolean,
        default: false,
    },
    showFileList: {
        type: Boolean,
        default: true,
    },
    //定义上传附件要传递的字段
    source: {
        type: String,
        default: "",
    }
});

const { proxy } = getCurrentInstance();
const emit = defineEmits(["uploadSuccess"]);
const upload = ref()
const num = ref(0);
const uploadList = ref([]);
// 上传的基准地址
const baseUrl = "";
// 上传接口地址
const uploadFileUrl = `${import.meta.env.VITE_API_BASE_URL}/api/upload`
// 请求头
const headers = { Authorization: "Bearer " };
const fileList = ref();
const upLoading = ref(false)
const upProgress = ref(0)
const showTip = computed(
    () => props.isShowTip && (props.fileType || props.fileSize)
);
const fileData = reactive({
    'source': props.source
})

watch(
    () => props.modelValue,
    (val) => {
        if (val) {
            let temp = 1;
            // 首先将值转为数组
            const list = Array.isArray(val)
                ? val
                : (props.modelValue?.toString().split(","));
            // 然后将数组转为对象数组
            fileList.value = list.map((item) => {
                if (typeof item === "string") {
                    item = { name: item, url: item };
                }
                item.uid = item.uid || new Date().getTime() + temp++;
                return item;
            });
        } else {
            fileList.value = [];
            return [];
        }
    },
    { deep: true, immediate: true }
);

// 上传前校检格式和大小
const handleBeforeUpload = (file) => {
    // 校检文件类型
    if (props.fileType.length) {
        let fileExtension = "";
        if (file.name.lastIndexOf(".") > -1) {
            fileExtension = file.name.slice(file.name.lastIndexOf(".") + 1);
        }
        const isTypeOk = props.fileType.some((type) => {
            if (file.type.indexOf(type) > -1) return true;
            if (fileExtension && fileExtension.indexOf(type) > -1) return true;
            return false;
        });
        if (!isTypeOk) {
            ElMessage.error(
                `文件格式不正确, 请上传${props.fileType.join("/")}格式文件!`
            );
            return false;
        }
    }
    // 校检文件大小
    if (props.fileSize) {
        const isLt = file.size / 1024 / 1024 < props.fileSize;
        if (!isLt) {
            ElMessage.error(`上传文件大小不能超过 ${props.fileSize} MB!`);
            return false;
        }
    }
    // ElMessage.loading("正在上传文件，请稍候...");
    upLoading.value = true;
    num.value++;
    return true;
};

// 文件个数超出
const handleExceed = (files) => {
    if (props.isExceed) {
        upload.value.clearFiles()
        const file = files[0]
        file.uid = genFileId()
        upload.value.handleStart(file)
        upload.value.submit()
    } else {
        ElMessage.error(`上传文件数量不能超过 ${props.limit} 个!`);
    }
};

// 上传失败
const handleUploadError = (err) => {
    upload.value = false
    ElMessage.error("上传文件失败");
};

// 上传成功回调
const handleUploadSuccess = (res, file) => {
    upLoading.value = false
    uploadList.value.push({ name: res.url, url: res.url });
    if (uploadList.value.length === num.value) {
        fileList.value = fileList.value
            .filter((f) => f.url !== undefined)
            .concat(uploadList.value);
        uploadList.value = [];
        num.value = 0;
        const resFiles = fileList.value.map(item => item.url)
        emit("update:modelValue", resFiles);
        emit("uploadSuccess", res.url);
    }
};

// 上传进度
const handleProgress = (evt, uploadFile, uploadFiles) => {
    upProgress.value = Math.round((evt.percent * 100)) / 100
    if (evt.percent === 100) {
        upLoading.value = false
    }
}

// 删除文件
const handleDelete = (index) => {
    fileList.value.splice(index, 1);
    emit("update:modelValue", listToString(fileList.value));
};

// 获取文件名称
const getFileName = (name) => {
    if (name.lastIndexOf("/") > -1) {
        return name.slice(name.lastIndexOf("/") + 1);
    } else {
        return "";
    }
};

// 对象转成指定字符串分隔
const listToString = (list, separator) => {
    let strs = "";
    separator = separator || ",";
    for (let i in list) {
        if (undefined !== list[i].url) {
            strs += list[i].url + separator;
        }
    }
    return strs !== "" ? strs.substring(0, strs.length - 1) : "";
};
</script>

<style scoped lang="scss">
.upload-file-uploader {
    margin-bottom: 5px;
}

.upload-file-list .el-upload-list__item {
    padding: 20px 0;
    border: 1px solid #e4e7ed;
    line-height: 2;
    margin-bottom: 10px;
    position: relative;
}

.upload-file-list .ele-upload-list__item-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: inherit;
    padding: 2px 12px;
}

.ele-upload-list__item-content-action .el-link {
    margin-left: 16px;
}
</style>

